Process for the preparation of macrocyclic polyazacarboxylate ligands and chelates

Patent metadata

Field	Value
Publication number	US-9777022-B2
Application number	US-201615061649-A
Country	US
Kind code	B2
Filing date	Mar 4, 2016
Priority date	Oct 2, 2012
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

The present disclosure relates generally to a process for the synthesis of 1,4,7,10-tetraazacyclododecane ligands, chelates, and derivatives thereof. In particular, the present disclosure is directed to a process for the synthesis of 1,4,7,10-tetraaza-1,4,7,10-tetrakis(carboxymethyl)cyclododecane (DOTA) ligands, corresponding DOTA-metal chelates, and various derivatives thereof.

First claim

What is claimed is:

1. A process for the preparation of 1,4,7,10-tetraaza-1,4,7,10-tetrakis(carboxymethyl)cyclododecane (DOTA), the process comprising:
(i) forming a reaction mixture comprising (a) a stoichiometric amount of an aziridine of Formula (Ib), (b) a Brønsted acid, and (c) a solvent; and,
(ii) reacting the contents of the reaction mixture to form DOTA by cyclotetramerization of the aziridine of Formula (Ib), according to the following reaction:

wherein:
HX 1 is a Brønsted acid;
Z 1 is an alkali metal having a +1 charge or an alkaline earth metal having a +2 charge; and
q and rare 1 when Z 1 is an alkali metal and q and rare 2 when Z 1 is an alkaline earth metal.

2. The process of claim 1 wherein the Brønsted acid is selected from the group consisting of p-toluenesulfonic acid, methane sulfonic acid, triflic acid, sulfuric acid, hydrochloric acid, hydroiodic acid, hydrobromic acid, hydrofluoric acid, phosphoric acid, perchloric acid, trifluoroacetic acid, triethylammonium chloride, triethylammonium bromide, triethylammonium acetate, triethylammonium formate, tris(2-hydroxyethyl)ammonium chloride, tris(2-hydroxyethyl)ammonium bromide, tris(2-hydroxyethyl)ammonium acetate, tris(2-hydroxyethyl)ammonium formate, 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosan-1-ium chloride, bromide, tris(2-hydroxyethyl)ammonium acetate, 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosan-1-ium formate, bis(isopropyl)ethylammonium chloride, bis(isopropyl)ethylammonium bromide, bis(isopropyl)ethylammonium acetate, bis(isopropyl)ethylammonium formate, tris(carboxymethyl)ammonium chloride, tris(carboxymethyl)ammonium bromide, tris(carboxymethyl)ammonium acetate, tris(carboxymethyl)ammonium formate, 2-(bis(carboxymethyl)amino)-N,N-bis(carboxymethyl)ethanaminium chloride, 2-(bis(carboxymethyl)amino)-N,N-bis(carboxymethyl)ethanaminium bromide, 2-(bis(carboxymethyl)amino)-N,N-bis(carboxymethyl)ethanaminium acetate, bis 2-(bis(carboxymethyl)amino)-N,N-bis(carboxymethyl)ethanaminium formate, 2-(bis(carboxymethyl)amino)-N-(2-(bis(carboxymethyl)amino)ethyl)-N-(carboxymethyl)ethanaminium, 2-(bis(carboxymethyl)amino)-N-(2-(bis(carboxymethyl)amino)ethyl)-N-(carboxymethyl)ethanaminium bromide, 2-(bis(carboxymethyl)amino)-N-(2-(bis(carboxymethyl)amino)ethyl)-N-(carboxymethyl)ethanaminium acetate, 2-(bis(carboxymethyl)amino)-N-(2-(bis(carboxymethyl)amino)ethyl)-N-(carboxymethyl)ethanaminium formate, formic acid, acetic acid, succinic acid, benzoic acid, lactic acid, citric acid, oxalic acid, nitriloacetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentacetic acid and combinations thereof.

3. The process of claim 1 wherein the Brønsted acid is selected from the group consisting of p-toluenesulfonic acid, trifluoroacetic acid, hydrochloric acid and sulfuric acid.

4. The process of claim 1 wherein Z 1 is Na + , K + , Ca 2+ or Mg 2+ and X 1 is Br − , Cl − or OSO 3 2− .

5. The process of claim 1 wherein the amount of the Brønsted acid, expressed as the ratio of equivalents of the acid to equivalents of aziridine, is from about 0.01:1 to about 0.5:1, from about 0.03:1 to about 0.1:1, or from about 0.04:1 to about 0.08:1.

6. The process of claim 1 further comprising treating DOTA with a metal cation, M n+ , wherein n+ is 2 or 3, provided from a metal ion source selected from the group consisting of metal oxides, metal carbonates, and weak chelates to form a metal-DOTA chelate of Formula (IIb) or Formula (IIc):

wherein the metal cation is selected from the group consisting of Gd, Eu, Tb, Dy, Sm, Lu, La, In, Ga, Re, Ru, Fe, Cu, Zn, Ni, Co, Cr, V, Ti Sc, Zr, Nb, Mo, Rh, Pd, Ag, Cd, Sn, Hf, Ta, W, Os, Ir, Pt, Au and Y, and wherein M 2+ coordination can occur with any two of the carboxyl moieties.

7. The process of claim 6 wherein the metal ion source is a chelate of acetylacetonate or Gd 2 O 3 and compound Formula (IIc) is gadoteric acid.

8. The process of claim 1 wherein the solvent comprises water.

9. The process of claim 8 wherein the solvent consists essentially of water.

10. The process of claim 1 wherein aziridine Formula (Ib) is prepared according to the following reaction scheme:

wherein X is a leaving group, X 2 is a halide, Z 1 is an alkali metal having a +1 charge or an alkaline earth metal having a +2 charge, q is 1 when Z 1 has a +1 charge, and q is 2 when Z 1 has a +2 charge.

11. The process of claim 10 wherein X is Cl, Br or OSO 3 − , the base is NaOH or KOH and Z 1 is Na + , K + , Ca 2+ or Mg 2+ .

12. The process of claim 1 wherein the reaction temperature is from about −20° C. to about 150° C., from about 0° C. to about 100° C., from about 10° C. to about 50° C., or from about 20° C. to about 30° C.

13. The process of claim 1 wherein the concentration of the aziridine in the reaction mixture is from about 0.05 to about 1.0 equivalents per liter, from about 0.1 to about 0.5 equivalents per liter, or from about 0.1 to about 0.3 equivalents per liter.

14. The process of claim 6 further comprising purifying reaction product Formula (IIb), Formula (IIc), or gadoteric acid and isolating reaction product Formula (IIb), Formula (IIc), or gadoteric acid, wherein
(i) the purity of the compound Formula (IIb), Formula (IIc), or gadoteric acid is at least about 50%, at least about 60%, at least about 70%, at least about 80%, or at least about 90% as measured by MS chromatogram, or
(ii) the molar yield of the compound Formula (IIb), Formula (IIc), or gadoteric acid is at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, or at least about 90% based on equivalents of aziridine.

15. The process of claim 14 wherein purification is by nanofiltration.

16. The process of claim 15 wherein the gadoteric acid is nanofiltered as the meglumine salt thereof.

17. The process of claim 15 wherein the DOTA is nanofiltered as the sodium salt thereof.

18. The process of claim 14 wherein isolation is by crystallization from aqueous solvent at a pH of from about 1 to about 4.

19. The process of claim 18 wherein the reaction product is gadoteric acid and the crystallization pH is from about 2 to about 4.

20. The process of claim 1 further comprising purifying reaction product DOTA and isolating reaction product Formula (IIb), Formula (IIc), DOTA or gadoteric acid, wherein
(i) the purity of the compound DOTA is at least about 50%, at least about 60%, at least about 70%, at least about 80%, or at least about 90% as measured by MS chromatogram, or
(ii) the molar yield of the compound DOTA is at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, or at least about 90% based on equivalents of aziridine.

21. A process for the preparation of a macrocyclic tetramer compound of Formula (IIe), the process comprising:
(i) forming a reaction mixture comprising (a) a stoichiometric amount of an aziridine of Formula (Ib), (b) a Lewis acid, and (c) a solvent; and,
(ii) reacting the contents of the reaction mixture to form a metal-1,4,7,10-tetraaza-1,4,7,10-tetrakis(carboxymethyl)cyclododecane (DOTA) chelate of Formula (IIe) by cyclotetramerization of the aziridine of Formula (Ib)

Assignees

• Mallinckrodt Llc
• Guerbet Sa

Inventors

• Moore Dennis A
• Rajagopalan Raghavan

Classifications

• C07F5/003 Primary

  without C-Metal linkages · CPC title

• C07D257/02 Primary

  not condensed with other rings · CPC title

• C07D295/15

  to an acyclic saturated chain · CPC title